This invention relates to an oil treating agent, in particular, to an oil treating agent directed to solidify e.g. Tempura-oil for domestic use or a waste oil from food oils for business use.
Conventionally, when treating a Tempura-oil used for deep-fried foods or waste food oil from food business (hereinafter referred to as waste oil), the waste oil is solidified by throwing a low-molecular polyethylene or paraffin thereinto and then is discarded. The invention described in Japanese Patent Application Publication No. Sho 60-054092 presents a solidification treatment of waste food oil comprising: adding a proper amount of 12-hydroxystearic acid to the waste food oil; dissolving it therein by heating in the absence of water; and then cooling the resultant mixture. The invention mentioned in Japanese Patent Application Laid-Open No. Hei 9-013072 provides a method for saponifying a fat and oil liquid at normal temperatures with alkali of e.g. sodium hydroxide or potassium hydroxide, which method comprises saponifying it with ⅙ to ⅓ of amount of alkali required for the complete saponification and then using a solvent-based (homogeneous system) saponification accelerator to solidify the fat and oil in about 1 to 3 minutes after the beginning of the saponification.
However, there is a problem that the waste oil never solidifies unless the low-molecular polyethylene or paraffin is added to the waste oil still remaining at high temperatures.
The invention disclosed in Japanese Patent Application Publication No. Sho 60-054092 is accompanied with a problem that the waste oil never gets solid unless the additive is added to the waste oil still staying at high temperatures, and hence the cooled oil must be heated before the solidification treatment. The waste oil never solidifies until it is cooled down to room temperature, and hence it brings about a problem of taking a lot of trouble and time.
According to the invention of Japanese Patent Application Laid-Open No. Hei 9-013072, the waste oil may solidifies between room temperature and about 90xc2x0 C., however, the contact area between the saponification accelerator and waste oil is still small because the saponification accelerator is a homogeneous solution, and the saponification accelerator hardly mixes with the waste oil because the compatibility therebetween is low, thus taking a lot of trouble with the mixing. Furthermore, because such a saponification accelerator is not so mixable as to hardly accelerate the saponification reaction, the reaction has to need an excess amount of strong alkali. When the strong alkali having a corrosive property is contacted with human body, it may undesirably damage the skin. Also, it is apprehended that the corrosiveness of strong alkali corrodes even metals, and also there is a fear that the corrosiveness may erode cooking utensils e.g. Tempura pans, which is not preferable.
Considering the demerits of the prior arts, the object of the present invention is to provide an oil treating agent capable of solidifying the waste oil, easily mixable with the waste oil, and allowed to reduce the usage of strong alkali.
All references herein to measurement percentages are understood to refer to weight percentages, unless otherwise noted.
A first oil treating agent of the invention, directed to solve the above problems, is a W/O emulsion comprising an oily continuous phase and an aqueous dispersed phase dispersed therein, wherein the dispersed phase is an alkaline mixture solution obtained by mixing water, a solution comprising water and an alcohol, or a water-free alcohol solution with an alkali hydroxide e.g. sodium hydroxide or with a metal alkoxide e.g. sodium alkoxide, and wherein the continuous phase comprises a liquid incompatible with the dispersed phase.
A second oil treating agent of the invention is a W/O emulsion according to the first oil treating agent, wherein a surface-active agent is employed as a dispersant for dispersing the dispersed phase in the continuous phase.
A third oil treating agent of the invention is according to the second treating agent, wherein the size of the particles forming the dispersed phase is no more than 15 xcexcm.
A fourth oil treating agent of the invention is according to the second treating agent, wherein the surface-active agent includes one or more kinds of surface-active agents selected from the group consisting of polyalkenylsuccinimide or its derivatives, polyalkenylsuccinamide or its derivatives, polyolefinamide-based compound or its derivatives, alkyl/alkenylamine-based compound or its derivatives, polyolefinamidealkene amine-based compound or its derivatives, polyoxyethylene-based compound, polyoxyphenylether-based compound, alkali metal soap-based compound, and alkali earth metal soap-based compound.
A fifth oil treating agent is according to the first oil treating agent, wherein the size of the particles of the dispersed phase no more than 15 xcexcm.
A sixth oil treating agent is according to the first oil treating agent, wherein the continuous phase is of mineral oil or synthetic oil.
A seventh oil treating agent is according to the sixth oil treating agent, wherein the continuous phase comprises one or more oil components selected from the group consisting of spindle oil, trans oil, neutral oil and bright stock oil (as a lubricant base oil viz. mineral oil); petroleumnaphtha, gasoline, kerosene and light oil (as a fuel oil); process oils.; liquid paraffins; and synthesis-based ether oil, synthesis-based polyalkylene glycol oil, synthesis-based polyalphaolefin, alkylbenzene oil and silicone oil (as a synthetic oil).
An eighth oil treating agent is a W/O emulsion which comprises the dispersed phase of a mixture solution comprising ethanol and a water dissolved with sodium hydroxide and the continuous phase of one or more kinds selected from the group consisting of paraffin hydrocarbon, olefin-based hydrocarbon and aromatic hydrocarbon each having a flash point of no less than 50xc2x0 C., wherein the dispersed phase in the form of particles with a size of about 10 xcexcm is dispersed in the continuous phase with the aid of surface-active agent.
A ninth treating agent is according to the first oil treating agent, wherein the dispersed phase comprises 2 to 30% of sodium hydroxide, 1 to 40% of water, and 2 to 80% of ethanol and the continuous phase is of mineral oil.
The oil treating agent of the invention is a W/O emulsion comprising the dispersed phase of an alkali hydroxide or alkaline mixture solution, accordingly, it disperses a small amount of countless alkaline particles in the waste oil to start the saponification reaction when added to the waste oil. In this case, such alkaline particles may be uniformly dispersed in the waste oil; a small amount of alkali provides the sufficient contact area between the alkaline solution and waste liquid because the alkaline particles are of liquid; and hence the waste oil may be quickly treated for solidification.